C70 T5 starts after 10-15sec org…

Good evening forum! I’ve been tormenting Aunt Google for a long time now, what it might be about… Starter goes through wacky, after about 10sec (or sometimes 3, ider 15s) the engine then goes off abruptly and runs clean on all cylinders. The stationary gas evenly. I exclude LMM, because the engine starts just as ticky when the LMM is plugged off. It goes out when I plug in the LMM then. Empty speed controller is suspected. But does not fluctuate the speed. Also, does not go out. Nocks, or crankshaft sensor? Symptoms? I don’t know. Power is 100% there when it runs. Petrol pressure regulator? Does the ignition system stop too late? I also exclude the immobilizer. Also, I think that the nozzles won’t drip, otherwise it wouldn’t run saube and the Lambda would complain. Do you have any ideas? Ohso, no, error memory is not (yet) read out.